Electromagnet.



N0. 815,365. PATBNTED MAR. 20, 1906.

E. H. MILLER. ELECTROMAGNET.

APILIUATIOH FILED 11037.26, 1904.

2 SHEETS-SHEET 1.

We? axes,

PATENTED MAR. 20, 1896.

E. H. MILLER.

ELEGTROMAGNET.

urmouwn rum) NOV. 26, 1904.

2 SHEETS-SHEET 2.

UNITED STATES PATENT OFFICE.

ERNEST H. MILLER, OF LANCASTER, PENNSYLVANIA, ASSIGNOR OF ONE- THlRD TO JOHN A. HOLMAN AND ()Nl l llllR-l) 'lO CHARLES V. ROTE.

OF LANCASTER, PENNSYLVANIA.

ELECTROMAGN ET.

Specification of Letters Patent.

Patented March 20, 19MB.

To all when-t it may concern:

Be it known that I, Eanns'r H. MILLER, a citizen of the United States, residing at Lencaster, in the county of Lancaster and State of Pennsylvania, have invented certain new and useful Irn rovements in Electromagnets; and I do here y declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

his invention relates to electrornotive power devices, and especially to solenoids that are used to produce a rectilinear movement of a core for the purpose of imparting a similar movement to some connected piece oi apparatus-such, for instance, as s. reihveybroke.

The ob'ect of the invention is to produce a solenoid eving a. concentrated field of force .with small magnetic reluctance, so that the power developed will be large for a iven size of solenoid. This result is accompfiished by the construction and arrangement hereinafter set forth, and particulerly pointed out in the claims.

In the accompanying drawings, Figure 1 is a side elevation of e'solenoid, partly in sec tion, embodying my improvements. Fig. 2 is a pienvievv of a double solenoid. Fig. 3 is a. similar view of s. modification of the same, partly in section. Fi 4 is a cross-section on the line 5 5, Fi 3. l ig. 5 is a side elevation of one end of l ig. 3, and Fig. 6 is an end elevation of the some.

Referring first to Fig. 1 the spool 1 is made of some non-Ina netic material. such as brass or copper. ts ends 2 are referahlv of iron, as is also the incasing s ell 3. The winding is divided into a plurality of sections, six being shown. The insulated wire 4 is Wound in each section beck and forth in corn centric leyers like the thread on e spool of thread, and the outer terminal of one section is connected with the inner tenninel of the next section, so that all the sections are in series The sevcrci sections may he separated by thin ertitions 5 of fiber or the like. This mode oi construction enables me to strengthen or weaken any given solenoid by mere y adding or taking away one or more sections, as t e case may be. The cores 6 .are simple cylindersof soft iron, adapted to slide freely within the spool 1. It will he seen that the magnetic circuit is through the ends 2 and shell 3, the portions of the cores within the spool 1, and the airap between the inner ends of the cores. In order to reduce the magnetic reluctance of this latter ortion of the circuit, I may introduce an lIOIl plug 7 midway of the spool, said plug serving, as it were, as a stepping-stone for the ma nctic flux. The plug is prcferehl solid, as s iown; but it may be tubular, if desired. The air-gap between it and the cores may he still further reduced by providing these ports with cooperating tapered projections 8 and recesses 9, the projections being preferably on the plug and the recesses in the cores, as shown.

When large sizes oi these solenoids are desired, it is found that the iron shell must be made very thick in order to provide a good magnetic circuit. in order to avoid the expense of so heavy or structure, I prefer to employ two smaller solenoids arranged side by side and acting on cores that are yoked together. Such a structure is shown in Figs. 2 and 3. The windings of the two solenoids i0 11 are connected in series like the coils on a horseshoe-electromagnet, so that the north pole of solenoid 10 1s ad'acent to the south pole of solenoid 11, an vice verse. The cores i2 13 at one end are rigidly connected by en iron yoke 14, and similarly the cores 15 16 at the other end are rigidly connected by a yoke 17. The yokes may be fastened to the cores or cast integral therewith. The end pieces 18 of the solenoids ere in this case made of non-ma netic nieteriel, such as brass, and the shel s 19 may also he made of similar material. The object of this is to compel the magnetic flux to pass only through the cores12 i3 i5 16, the yokes 14 17, end the air-gs. s inside the spools. The okes are made 0 suficient cross-section to carry the flux easily.

If desired, these solenoids may be provided with the midway plugs 7, preferably provided with the tepering projections 8. In Fig. 3 these plugs are carried by a plug yoke or hrid e 20, which is interposed between the mid le sections of the coils and passes through openings cut in the shells. This brid e is of iron, and a convenient way of at- 1 tachnig the plugs to it is to provide them with screw threaded shanks 21, engaging with tapped holes in the brid e. A sma ortion of each plug is prefera )ly made cylindrical to fi t the end of the spool, the opposite end of which is let into the end plate of the solenoid.

By preference suitable guides are provided to keep the cores in position. For example, a bifurcated bar 22 may be fastened to the yoke, one jaw being longer than the other and provided with a longitudinal slot 23, which engages with a stud or roller 24, supported by a stationar bracket 25. In case one of the solenoids s ould become inoperative, as by short-circuiting, this guide will hold the cores in proper alinement and enable the operative solenold to do effective work It also prevents the outer ends of the cores from sagging when in their outermost position. T he guide also forms a convenient means for the attachment of the lever or other agency through which the pull of the solenoids is transmitted to the desired mechanism.

It will be understood, of course, that my invention may be embodied in various forms, and various changes may be made in the details and arrangement of parts without departing from the spirit and scope of my invention, of which the several embodiments shown and described herein are desirable forms.

Having thus described my invention, what I claim is- 1. A solenoid for power purposes, comprising a tubular spool of non-magnetic material, a magnetic plug midway of said spool, a plurality of coil-sections wound on said spool and connected in series, and movable cores entering said spool, said plug and cores having cooperating projections and recesses.

2. An electromotive power device, comprising two solenoids side by side, each haylng a plurality of coil-sectlons connected in series, and adjacent ends of the windings on said solenoids being connected, movable cores entering the opposite ends of said solenoids, and yokes connecting adjacent cores.

3. An electromotive oWer device, comprisin two solenoids siie by side, eachhavmg a p urality of coil-sections connected 1n series, and adjacent ends of the windings on said solenoids bein connected, ma netic plugs midway of sai solenoids, mova 1e cores entering the opposite ends of said solenoids, and yokes rigidly connecting adjacent cores.

4. The combination Wlth two solenoids arranged side by side, of a bridge of magnetic material arranged midway thereof and movable cores yoked together entering the opposite ends thereof.

5. The combination with two solenoids arranged side by side and each composed of a plurality of coil-sections connected in series, of a magnetic bridge inter )osed between the middle sections, and movable cores yoked together entering the opposite ends of said soenolds.

6. The combination with two solenoids arranged side by side and each composed of a plurality of coil-sections connected in series,

the windings on the two solenoids being also connected in series, of a ma netic bridge interposed between the midfie coil-sections, and movable cores entering the ends of said solenoids and connected by rigid yokes, said bridge and cores having cooperating projections and recesses.

7. The combination with two solenoids ar ranged side by side and connected in series, of movable cores entering the opposite ends thereof, a oke at each end of the solenoids to which said cores are connected, and a guide for each yoke.

8 The combination with two solenoids arranged side by side and connected in series, of movable cores enterin the ends thereof, a yoke at each end to Whic said cores are connected, a bifurcated slotted bar fastened to each yoke, and a stud enga ing with said slot.

9. The combination with two solenoids arranged side by side, of a ma netic bridge ar ranged intermediate the ends of each solenoid, and connected movable cores entering opposite ends of said solenoids.

10. The combination with two solenoids arranged side by side, each composed of a plurality of coil-sectionsconnected in series, of a magnetic bridge interposed between the middle coil-sections, and connected movable cores entering opposite ends of said solenoids.

11. The combination of two solenoids arranged side byside, each comprising a tubular spool of non-ma netic material, a plurality of removable coi -sections wound thereon side by side and connected in series, and movable eores entering the opposite ends of said spools.

In testimony whereof I afiix my signature in presence of two witnesses.

ERNEST H. MILLER.

Witnesses:

GEO. A. LANE, C. G. BASBLER. 

